SC 13G

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G
(Rule 13d-102)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO
RULES 13d-1(b), (c) AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO
RULE 13d-2(b)

PHASE FORWARD INCORPORATED

(Name of Issuer)

Common Stock (Par Value $0.01 Per Share)

(Title of Class of Securities)

71721R406

(CUSIP Number)

December 31, 2004

(Date of Event which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

	o	Rule 13d-1(b)
	o	Rule 13d-1(c)
	x	Rule 13d-1(d)

CUSIP No. 71721R406

1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) Thomas Weisel Partners Group LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) o (b) x
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5	SOLE VOTING POWER 0
		6	SHARED VOTING POWER 2,721,320
		7	SOLE DISPOSITIVE POWER 0
		8	SHARED DISPOSITIVE POWER 2,721,320
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,721,320
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* o
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 8.4%
12	TYPE OF REPORTING PERSON* OO – HC

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CUSIP No. 71721R406

1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) Tailwind Capital Partners LLC
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) o (b) x
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5	SOLE VOTING POWER 0
		6	SHARED VOTING POWER 2,686,529
		7	SOLE DISPOSITIVE POWER 0
		8	SHARED DISPOSITIVE POWER 2,686,529
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,686,529
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* o
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 8.3%
12	TYPE OF REPORTING PERSON* OO

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CUSIP No. 71721R406

1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) Thomas Weisel Capital Partners, L.P.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) o (b) x
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5	SOLE VOTING POWER 0
		6	SHARED VOTING POWER 2,308,580
		7	SOLE DISPOSITIVE POWER 0
		8	SHARED DISPOSITIVE POWER 2,308,580
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,308,580
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* o
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 7.1%
12	TYPE OF REPORTING PERSON* PN

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CUSIP No. 71721R406

1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) TWP CEO Founders’ Circle (QP), L.P.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) o (b) x
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5	SOLE VOTING POWER 0
		6	SHARED VOTING POWER 194,869
		7	SOLE DISPOSITIVE POWER 0
		8	SHARED DISPOSITIVE POWER 194,869
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 194,869
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* o
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 0.6%
12	TYPE OF REPORTING PERSON* PN

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CUSIP No. 71721R406

1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) TWP CEO Founders’ Circle (AI), L.P.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) o (b) x
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5	SOLE VOTING POWER 0
		6	SHARED VOTING POWER 53,337
		7	SOLE DISPOSITIVE POWER 0
		8	SHARED DISPOSITIVE POWER 53,337
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 53,337
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* o
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 0.2%
12	TYPE OF REPORTING PERSON* PN

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CUSIP No. 71721R406

1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) Thomas Weisel Capital Partners (Dutch), L.P.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) o (b) x
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5	SOLE VOTING POWER 0
		6	SHARED VOTING POWER 54,009
		7	SOLE DISPOSITIVE POWER 0
		8	SHARED DISPOSITIVE POWER 54,009
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 54,009
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* o
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 0.2%
12	TYPE OF REPORTING PERSON* PN

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CUSIP No. 71721R406

1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) Thomas Weisel Capital Partners (Dutch II), L.P.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) o (b) x
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5	SOLE VOTING POWER 0
		6	SHARED VOTING POWER 54,009
		7	SOLE DISPOSITIVE POWER 0
		8	SHARED DISPOSITIVE POWER 54,009
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 54,009
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* o
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 0.2%
12	TYPE OF REPORTING PERSON* PN

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CUSIP No. 71721R406

1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) Thomas Weisel Capital Partners Employee Fund, L.P.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) o (b) x
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5	SOLE VOTING POWER 0
		6	SHARED VOTING POWER 21,725
		7	SOLE DISPOSITIVE POWER 0
		8	SHARED DISPOSITIVE POWER 21,725
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 21,725
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* o
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 0.07%
12	TYPE OF REPORTING PERSON* PN

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CUSIP No. 71721R406

1	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY) TWP 2000 Co-Investment Fund, L.P.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) o (b) x
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5	SOLE VOTING POWER 0
		6	SHARED VOTING POWER 34,791
		7	SOLE DISPOSITIVE POWER 0
		8	SHARED DISPOSITIVE POWER 34,791
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 34,791
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* o
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 0.1%
12	TYPE OF REPORTING PERSON* PN

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Item 1(a). Name of Issuer:

Phase Forward Incorporated

Item 1(b). Address of Issuer’s Principal Executive Offices:

880 Winter Street, Waltham, MA 02451-1464

Item 2(a). Name of Persons Filing:

1.	Thomas Weisel Partners Group LLC (“TW Group”)
2.	Tailwind Capital Partners LLC (“TCP LLC”)
3.	Thomas Weisel Capital Partners, L.P. (“TWCP LP”)
4.	TWP CEO Founders’ Circle (QP), L.P. (“QP”)
5.	TWP CEO Founders’ Circle (AI), L.P. (“AI”)
6.	Thomas Weisel Capital Partners Employee Fund, L.P. (“Employee Fund”)
7.	Thomas Weisel Capital Partners (Dutch), L.P. (“TWCP Dutch”)
8.	Thomas Weisel Capital Partners (Dutch II), L.P. (“TWCP Dutch II”)
9.	TWP 2000 Co-Investment Fund, L.P. (“TWP 2000”)

Numbers 1 through 9 above, the “Filing Persons”.

The Filing Persons are filing this Schedule 13G jointly pursuant to a Joint Filing Agreement dated February 14, 2005 attached hereto as Exhibit 1.

Item 2(b). Address of Principal Business Office or, if None, Residence:

The principal business address for TW Group and TWP 2000 is One Montgomery Street, Suite 3700, San Francisco, CA 94104. The principal business address of each of the other reporting persons is 390 Park Avenue, 17^th Floor, New York, NY 10022.

Item 2(c). Citizenship:

The jurisdiction of incorporation for each of the Filing Persons is Delaware.

Item 2(d). Title of Class of Securities:

Common Stock, par value $0.01 per share, of the Issuer (the “Common Stock”).

Item 2(e). CUSIP Number:

71721R406

Item 3. If this Statement is Filed Pursuant to Rule 13d-1(b), or 13d-2(b) or (c), Check Whether the Person Filing is a:

(a)	o	Broker or dealer registered under Section 15 of the Exchange Act;

(b)	o	Bank as defined in Section 3(a)(6) of the Exchange Act;

(c)	o	Insurance company as defined in Section 3(a)(19) of the Exchange Act;

(d)	o	Investment company registered under Section 8 of the Investment Company Act;

(e)	o	An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);

(f)	o	An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F);

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(g)	o	A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G);

(h)	o	A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act;

(i)	o	A church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act;

(j)	o	Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

If this statement is filed pursuant to Rule 13d-1(c), check this box. o

Item 4. Ownership.

Provide the following information regarding the aggregate number and percentage of the class of securities of issuer identified in Item 1.

(a) Amount beneficially owned as of December 31, 2004:

TW Group	2,721,320+
TCP LLC	2,686,529^
TWCP LP	2,308,580
QP	194,869
AI	53,337
Employee Fund	21,725
TWCP Dutch	54,009
TWCP Dutch II	54,009
TWP 2000	34,791

+ Includes shares of Common Stock owned by TWCP LP, QP, AI, Employee Fund, TWCP Dutch, TWCP Dutch II and TWP 2000, which may be deemed to be beneficially owned by this Filing Person. TW Group is the managing member of an entity that is (i) the managing member of TCP LLC and (ii) the general partner of TWP 2000.

^ Includes shares of Common Stock owned by TWCP LP, QP, AI, Employee Fund, TWCP Dutch and TWCP Dutch II, which may be deemed to be beneficially owned by this Filing Person. TCP LLC is (i) the general partner of TWCP LP, AI, QP and Employee Fund and (ii) the managing member of the general partner of TWCP (Dutch) and TWCP (Dutch II).

(b) Percent of class as of December 31, 2004:

TW Group	8.4 %*+
TCP LLC	8.3 %*^
TWCP LP	7.1 %*
QP	0.6 %*
AI	0.2 %*
Employee Fund	0.07 %*
TWCP Dutch	0.2 %*
TWCP Dutch II	0.2 %*
TWP 2000	0.1 %*

* Represents percent of class based on 32,338,409 shares of Common Stock outstanding as reported on the Issuer’s 10-Q filed on November 10, 2004.

+ Percentage includes shares of Common Stock owned by TWCP LP, QP, AI, Employee Fund, TWCP Dutch, TWCP Dutch II and TWP 2000, which may be deemed to be beneficially owned by this Filing Person.

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^ Percentage includes shares of Common Stock owned by TWCP LP, QP, AI, Employee Fund, TWCP Dutch and TWCP Dutch II, which may be deemed to be beneficially owned by this Filing Person.

(c) Number of shares as to which such person had as of December 31, 2004:

	(i)	Sole power to vote or to direct the vote: 0
	(ii)	Shared power to vote or to direct the vote: Same response as in Item 4(a) above.
	(iii)	Sole power to dispose or to direct the disposition of: 0
	(iv)	Shared power to dispose or to direct the disposition of: Same response as in Item 4(a) above.

Item 5. Ownership of Five Percent or Less of a Class.

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following. o

Item 6. Ownership of More than Five Percent on Behalf of Another Person.

Not applicable.

Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company.

Not applicable.

Item 8. Identification and Classification of Members of the Group.

Not applicable.

Item 9. Notice of Dissolution of Group.

Not applicable.

Item 10. Certifications.

Not applicable.

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SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

February 14, 2005

THOMAS WEISEL PARTNERS GROUP LLC

By:	/s/ Jack Helfand

	Name:	Jack Helfand
	Title:	Associate General Counsel

TAILWIND CAPITAL PARTNERS LLC

By:	/s/ James S. Hoch

	Name:	James S. Hoch
	Title:	Managing Partner

TAILWIND CAPITAL PARTNERS LLC

By:	/s/ James S. Hoch

	Name:	James S. Hoch
	Title:	Managing Partner

THOMAS WEISEL CAPITAL PARTNERS, L.P.

TWP CEO FOUNDERS’ CIRCLE (QP), L.P.

TWP CEO FOUNDERS’ CIRCLE (AI), L.P.

THOMAS WEISEL CAPITAL PARTNERS
EMPLOYEE FUND, L.P.

By:	TAILWIND CAPITAL PARTNERS LLC, as General
	Partner of each of the limited partnerships named above

By:	/s/ James S. Hoch

	Name:	James S. Hoch
	Title:	Managing Partner

THOMAS WEISEL CAPITAL PARTNERS (DUTCH), L.P.

THOMAS WEISEL CAPITAL PARTNERS (DUTCH II), L.P.

By:	THOMAS WEISEL CAPITAL PARTNERS (DUTCH) LLC, as General Partner of each of the limited partnerships named above

By:	TAILWIND CAPITAL PARTNERS LLC, as Managing Member

By:	/s/ James S. Hoch

	Name:	James S. Hoch
	Title:	Managing Partner

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TWP 2000 CO-INVESTMENT FUND, L.P.

By:	THOMAS WEISEL CAPITAL MANAGEMENT
	LLC, as General Partner

By:	/s/ Jack Helfand

	Name:	Jack Helfand
	Title:	Associate General Counsel

The original statement shall be signed by each person on whose behalf the statement is filed or his authorized representative. If the statement is signed on behalf of a person by his authorized representative (other than an executive officer or general partner of the filing person), evidence of the representative’s authority to sign on behalf of such person shall be filed with the statement, provided, however, that a power of attorney for this purpose which is already on file with the Commission may be incorporated by reference. The name and any title of each person who signs the statement shall be typed or printed beneath his signature.

Attention. Intentional misstatements or omissions of fact constitute federal criminal violations (see 18 U.S.C. 1001).

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Exhibit 1

Joint Filing Agreement

The undersigned hereby agree that the Statement on Schedule 13G filed herewith (and any amendments thereto), relating to the Common Stock, par value $0.01 per share, of Phase Forward Incorporated, is being filed jointly with the Security and Exchange Commission pursuant to Rule 13d-1(k)(1) under the Securities and Exchange Act of 1934, as amended, on behalf of each such person.

Dated: February 14, 2005

THOMAS WEISEL PARTNERS GROUP LLC

By:	/s/ Jack Helfand

	Name:	Jack Helfand
	Title:	Associate General Counsel

TAILWIND CAPITAL PARTNERS LLC

By:	/s/ James S. Hoch

	Name:	James S. Hoch
	Title:	Managing Partner

TAILWIND CAPITAL PARTNERS LLC

By:	/s/ James S. Hoch

	Name:	James S. Hoch
	Title:	Managing Partner

THOMAS WEISEL CAPITAL PARTNERS, L.P.

TWP CEO FOUNDERS’ CIRCLE (QP), L.P.

TWP CEO FOUNDERS’ CIRCLE (AI), L.P.

THOMAS WEISEL CAPITAL PARTNERS
EMPLOYEE FUND, L.P.

By:	TAILWIND CAPITAL PARTNERS LLC, as General
	Partner of each of the limited partnerships named above

By:	/s/ James S. Hoch

	Name:	James S. Hoch
	Title:	Managing Partner

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THOMAS WEISEL CAPITAL PARTNERS (DUTCH), L.P.

THOMAS WEISEL CAPITAL PARTNERS (DUTCH II), L.P.

By:	THOMAS WEISEL CAPITAL PARTNERS (DUTCH) LLC, as General Partner of each of the limited partnerships named above

By:	TAILWIND CAPITAL PARTNERS LLC, as Managing Member

By:	/s/ James S. Hoch

	Name:	James S. Hoch
	Title:	Managing Partner

TWP 2000 CO-INVESTMENT FUND, L.P.

By:	THOMAS WEISEL CAPITAL MANAGEMENT
	LLC, as General Partner

By:	/s/ Jack Helfand

	Name:	Jack Helfand
	Title:	Associate General Counsel

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